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In August 2000, Gurit was commissioned by Baltic Yachts to provide structural engineering services for a 44 metre super cruising yacht, the Baltic 141. Gurit provided consultancy support from the initial stages of the yacht’s production to completion, throughout the extensive luxury fit-out, and up until the final proof testing phase of the deck fitting prior to sea trials. Alex Shimell, Gurit’s Client and Engineering Manager, describes this outstanding project that extends an already long and established relationship with Baltic Yachts.

The aim was to produce a luxury cruising yacht offering the best possible sailing performance using the technology and materials of a modern racing yacht. Keeping the structure lightweight and rigid whilst maintaining reliability was therefore a key focus, and Gurit’s Technical Services team liaised closely with Baltic on the process specification prior to construction.

PERFORMANCE, STYLE AND TECHNOLOGY – THE BALTIC 141

Gurit made extensive use of Finite Element Analysis (FEA) when engineering the Baltic 141. Designers Judel/Vrolijk provided the hull and deck shapes as 3D surfaces and Gurit then worked with these surfaces to create a detailed Finite Element (FE) model using Nastran/Patran software and laminate modeller. This aided the construction of a prototype of the keel and mast area of the boat. Advance planning of all the yacht’s systems by Baltic enabled all the conduits and systems penetrations to be incorporated into the FEA.

Having engineered other super yachts such as the Baltic 147, Mari-Cha III & IV, Gurit has a great deal of experience in FE modelling. Each project is different and the behaviour of the 141 structure posed three unique engineering challenges. These were local stress concentrations around the very highly loaded mast bulkhead, the composite shroud panels, and the local loads around the lifting keel.

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longitudinal stiffness in the hull as well as toughness and durability. Both the hull and deck were built over male plugs in one piece. Nomex honeycomb core materials were used predominately but Gurit® Corecell™ foam was applied in the hull bottom local interior panels for better sound insulation and to take the slamming loads the yacht will encounter at sea.

Working with the boat’s skipper, Jan Lindell, it was decided that Balsa core would be used on the topside to provide better dent resistance. Trial models of the hull laminate were produced at Baltic Yachts and Baltic then laminated a set of test panels which formed part of the approval by the Det Norske Veritas.

The Baltic 141 was completed in 2004 at Baltic’s yard in Finland. The yacht sets a new standard in the Super Cruising Yacht market and the owner intends to sail her around the world in various stages, undoubtedly attracting a great deal of attention on the water.

The interior design around the shroud bulkheads was modelled using FEA to increase the stiffness of the hull whilst minimising additional weight and without compromising the interior space. In designing the all composite carbon lifting keel box, Gurit worked with Roland Kasslind at R&J Design to develop the keel lift mechanism and locking systems to support the 53 tonne keel and bulb.

Gurit collaborated closely with the project manager Kenneth Nyfelt at Baltic Yachts and designed most of the composite design detail including the composite rudder quadrant, p-bracket, anchor arm, tender bay garage, transom hatch, the conduit system and penetration details.

All of the main composite components in the Baltic 141, including the hull and deck bulkheads, were built using Gurit’s SE84 prepreg. A predominantly high elongation carbon fibre was used with intermediate modulus carbon fore and aft. Glass, carbon and aramid fibres were applied to provide